QoS and switch delay on 1638P

[george_s]

I have a 1638P and have the following set up:

Bsmt24Port#sho qos cos

CoS Priority   : 0  1  2  3  4  5  6  7

Priority Queue : 1  1  2  2  3  3  4  4

Bsmt24Port#sho qos dscp

DSCP-CoS map:

DSCP: 46

----------------------------------

CoS: 6

Bsmt24Port#sho qos que

Queue-type: strict-priority

Expedite queue: n/a

Strict-priority levels:

qid - priority level

1  - lowest

2  -

3  -

4  - highest

Bsmt24Port#

Bsmt24Port#sho run int gi 0/15

Building configuration...

!

!

interface gigabit-switchport 0/15

spanning-tree edgeport

no shutdown

switchport access vlan 2

switchport voice vlan 3

qos trust cos

no lldp send-and-receive

I am seeing low MOS scores for individual calls throughout the day, with all of them showing delay for the reason of the low score. There is no pattern as to when this happens, and they are not a data intensive business. A wireshark capture confirms EF tagging

Phones are on VLAN 3, PC’s are VLAN 2 and plugged in the back of the phones.

Everything else appears ok. Are there any built in tools on the 1638, that will show switch cpu/memory/and queue load?

[Anonymous · Accepted solution]

- Thanks for posting your question on the forum!

I think the following commands are what you are looking for:

show proc cpu

show queue

show mem heap

Let us know if you have any further questions.

Thanks,

Noor

[phil_denton]

Is this the only switch in your environment?  If so, are you using "qos trust cos" on the uplink to your voice server (or the Internet if your phone system is cloud hosted)?  If not, are you using "qos trust cos" on both sides of every switch trunk?

[george_s]

Thanks for the reply Phil.  I am using qos trust on all switchports and trunks. The issue turned out to be a problem with a specific version of software on the VoIP phone system